Splenic marginal zone lymphoma: from genetics to management

Luca Arcaini, Davide Rossi and Marco Paulli


Splenic marginal zone lymphoma (SMZL) is a rare B-cell malignancy involving the spleen, bone marrow and, frequently, blood. SMZL lymphomagenesis involves antigen/super-antigen stimulation and molecular deregulation of genes (NOTCH2 and KLF2) regulating the physiological differentiation of spleen marginal zone B-cells. Diagnosis requires either spleen histology or, alternatively, the documentation of a typical cell morphology and immunophenotype on blood cells coupled with the detection of intrasinusoidal infiltration by CD20+ cells in the bone marrow. Among B-cell tumors, deletion of 7q and NOTCH2 mutations are almost specific lesions of SMZL, thus representing promising diagnostic biomarkers of this lymphoma. Although the majority of SMZL shows an indolent course with a median survival of approximately 10 years, ~30% of patients experience a poor outcome. No randomized trials are reported for SMZL and few prospective trials are available. A watch and wait approach is advisable for asymptomatic patients. Treatment options for symptomatic patients ranges from splenectomy to rituximab alone or combined to chemotherapy. In some geographic areas, a subset of SMZL associates with hepatitis C virus infection, prompting virus eradication as an effective lymphoma treatment. Deregulated cellular programs of SMZL are worthwhile to be explored as therapeutic targets in the next years; improved clinical and biological prognostication will be essential to identify patients who may benefit from novel approaches.

  • Submitted November 9, 2015.
  • Accepted March 7, 2016.